The statements in this section merely provide background information related to the present disclosure. Accordingly, such statements are not intended to constitute an admission of prior art.
Known powertrain architectures include torque-generative devices that generate and transfer torque via a torque transmission device to a driveline including one or more drive wheels for traction to propel a vehicle. Torque-generative devices may include, e.g., an internal combustion engine and/or torque machine(s) powered by non-fossil fuel. The torque machine(s) may use non-fossil fuels including, e.g., stored electric energy, stored hydraulic energy, and stored pneumatic energy, to generate tractive torque. The torque machine(s) may transform vehicle kinetic energy that is transmitted through the drive wheels to energy that is storable in an energy storage device.
Known hybrid powertrain systems are configured to stop and start the internal combustion engine during ongoing powertrain operation using autostop and autostart control schemes. Known hybrid powertrain systems may use a separate starter motor, or alternatively, use the torque machine to provide torque to spin and start the engine. Using the torque machine to provide torque to spin and start the engine may include gradually applying a torque transfer clutch while spinning the torque machine to spin the engine. This process consumes a substantial amount of power from the torque machine, and requires a calibrated control scheme to control operation of the torque transfer clutch. Torque spikes associated with engine cylinder compression and firing may be directly transferred to the torque machine.